1. Field of the Invention
The present invention is directed in general to communications systems and methods for operating same. In one aspect, the present invention relates to the methods, systems and devices for managing coexistence interference between different radio technologies deployed in adjacent bands.
2. Description of the Related Art
The growing market of smart connected devices requires that the same device supports multiple radio technologies on the in-device platform. However, some configurations may cause severe performance degradation due to the in-device coexistence interference. For example, with devices that support both Long Term Evolution (LTE) and Industrial, Science and Medical (ISM) technologies (such as Bluetooth and/or WLAN) and/or Global Navigation Satellite System (GNSS) technologies, there are use cases for concurrent operation of these radios. The coexistence issues arise between ISM and/or GNSS technologies and LTE deployed in adjacent bands. As shown in Table 1 below, coexistence interference arises where ISM transmission creates interference to the LTE receiver, and also arises where LTE transmission creates interference to the ISM receiver.
TABLE 1Interference of the LTE and ISM components on the in-deviceconfigurationLTE TDD (2.3-2.4 GHz, Band 40)ISMLTE UL (2.5-2.6 GHz, Band 7)(2.4-2.4835 GHz)CoexistenceRxTxLTE: InterferedISM: NormalTxRxLTE: NormalISM: Interfered
Similar coexistence issues occur with devices that include both LTE and GNSS components. As shown in Table 2 below, when LTE and GNSS components are working on the same device, there will be interference due to adjacent frequency band operation or harmonic frequencies which cannot be avoided by the allocation of a guard band at the sub-harmonic frequency.
TABLE 2Interference of the LTE and GNSS component configuration on in-deviceLTEGNSS(777-787 MHz/746-756 MHz, Band 13)(1575.42(788-798 MHz/758-768 MHz, Band 14)MHz)CoexistenceTxRxLTE: NormalGNSS: Interfered
As will be appreciated, there are challenges to using current state-of-the-art filter technology to address coexistence interference since terminal filters do not provide sufficient rejection on the adjacent channel interference. These challenges are particularly acute in the case of these components configured in a single device where the interference occurs when the LTE component is transmitting on the specified bands. Accordingly, a need exists for improved method, system and device for managing coexistence interference between different radio technologies to overcome the problems in the art, such as outlined above. Further limitations and disadvantages of conventional processes and technologies will become apparent to one of skill in the art after reviewing the remainder of the present application with reference to the drawings and detailed description which follow.